NEC will this week show a prototype notebook PC powered by its own fuel cell unit, the company said today.

The power supply marks a big improvement over NEC's previous fuel cell efforts, the company said, with what is effectively a 20 per cent reduction in the size of the cell for the same power output. Indeed, where the current prototype doesn't look out of place as part of the notebook's contruction, the previous version, shown over a year ago, had a rather large fuel cyclinder positioned behind the screen.

Last year's system had a power output density of 50mW per cm², compared to the 70mW per cm² NEC has managed to get out of the new model. The focus of NEC's development work is equipping the fuel cell with monitoring and management systems to ensure smooth, stable power generation.

Of course, it's all a very long way from commercialisation - NEC didn't provide any timeframe against which the release of a fuel cell-powered laptop might be measured. Interestingly, NEC was not so circumspect this time last year when it promised to bring a fuel cell-equipped notebook to market by the end of 2004. Back then, it also scheduled a similar machine capable of 40 hours' continuous operation to appear by the end of 2005.

NEC isn't the only Japanese company developing fuel cells for notebooks - so too is Toshiba and Hitachi, who have also demonstrated prototype systems this year. Intel-funded start up PolyFuel is also working on direct methanol fuel cells for laptops. So is German company Smart Fuel Cells.

Toshiba has also shown off cells aimed at PDAs, MP3 players and mobile phones, as has Hitachi. ®